Coded reverse link messages for closed-loop power control of forward link control messages

• US 20070206542A1
• Filed: 05/01/2007
• Published: 09/06/2007
• Est. Priority Date: 05/04/2001
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Proctor, James
• Application Number:
  US11/799,155
• Publication Number:
  US 20070206542A1
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04B 7/2637 for logical channel control
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Multiple field units in a CDMA system are synchronized for communication with a base station using shared forward and reverse link channels. In an illustrative embodiment, each field unit is assigned a time slot in a forward link channel to receive messages from the base station. Likewise, each field unit is assigned a time slot on a common reverse link channel for transmitting messages to the base station. Timing alignment and power level control among each of many field units and the base station is achieved by analyzing coded transmissions received at the base station in a corresponding time slot as transmitted by each field unit. The codes may be orthogonal, pseudonoise (PN), or other codes. The power level of forward control channel messages can thus be individually controlled. In this way, minimal resources are deployed to maintain communication and precise synchronization between a base station and each of multiple users, minimizing collisions between field units transmitting in adjacent time slots on the reverse link.

Claims

1. A method for supporting wireless communications, the method comprising:

assigning a field unit a first time slot in a reverse link channel;

receiving and analyzing messages from said field unit at a base station in the first time slot; and

maintaining synchronization between said field unit and said base station when said field unit is inactive or standby mode.

2. The method of claim 1 further comprising:

assigning said field unit a second time slot in a forward link channel.

4. The method of claim 2 further comprising:

said field unit indicating to said base station to remain in the standby mode.

5. The method of claim 2, wherein said reverse link channel is a heartbeat-type channel.

6. The method of claim 5, wherein said heartbeat-type channel comprises an active channel and a standby channel.

7. The method of claim 6 further comprising:

transmitting in said standby channel and indication to remain in the standby mode.

8. The method of claim 6 further comprising:

transmitting in said active channel a request for allocation of reverse link traffic channels for transmitting data.

9. The method of claim 6 further comprising:

transmitting power control information including whether messages over said forward link channel should be increased in power or decreased in power.

10. The method of claim 9 wherein said standby channel and said active channel include said power control information.

3. The method of 2, wherein said field unit transmits a timing reference signal in said first time slot when said first unit is in standby mode.

11. A system for supporting wireless communication comprising:

a base station for assigning a field unit a first time slot in a reverse link channel, and receiving and analyzing messages from said field unit in said first time slot; and

said base station and said field unit maintaining synchronization when said field unit is in an active mode or standby mode.

12. The system of claim 11 further comprising said base station for:

assigning said field unit a second time slot in a forward link channel.

13. The system of claim 12, wherein said field unit transmits a timing reference signal in said first time slot when said field unit is in standby mode.

14. The system of claim 12 further comprising:

said field unit indicating to said base station to remain in the standby mode.

15. The system of claim 12, wherein said reverse link channel is a heartbeat-type channel.

16. The system of claim 15, wherein said heartbeat-type channel comprises an active channel and a standby channel.

17. The system of claim 16 further comprising:

transmitting in said standby channel and indication to remain in the standby mode.

18. The system of claim 16 further comprising:

transmitting in said active channel a request for allocation of reverse link traffic channels for transmitting data.

19. The system of claim 16 further comprising:

transmitting power control information including whether messages over said forward link channel should be increased in power or decreased in power.

20. The system of claim 19 wherein said standby channel and said active channel include said power control information.